Abstract：The algae in simulated ballast water were rapidly killed by using hydroxyl radical produced by strong electric-field ionization discharge based on the Regulation no. D-2 of IMO "International Convention for the Control and Management of Ships' Ballast Water and Sediments". The experimental results show that the inactivation is very well achieved when the initial concentration of Isochrysis galbana, Synechococcus, Nitzschia closterium and the mixed algae of the three species are 1.1×104, 5.0×104, 4.0×104 and 2.4×104 cell/mL, respectively. And the death rate of all kinds of algae can reach 99.98% when the concentration of hydroxyl radical solution is 0.62 mg/L in the ballast water simulation treatment 6 s system after contacting time of 6 s in the discharge pipelines. Moreover, the resurrection of treated algae has not been found after 24 hours. And the results agree completely with the Regulation no. D-2, the discharge standards of the Convention. At the same time, the monitoring analysis shows that pH value, salinity, conductivity of the treated seawater are almost unchanged. Turbidity is decreased, while dissolved oxygen is increased. Total suspended solids are decreased to 85%. Chemical oxygen demand is decreased to a point of no detection. The amount of phosphate and the total content of inorganic nitrogen agree with the seawater quality standards also.
2009, Vol. 27 
